Putting solar photovoltaics (PV) directly on EVs would be nice but likely not adequate. Most solar panels would add too much weight. Some newer, lighter and flexible PV technology could generate power for interior climate control or minor tasks, but not enough to power a car a significant distance. Furthermore, cars are often parked in garages or under carports, where sunlight won’t reach.
Likewise, windmills on EVs don’t make sense. The drag they create reduces efficiency, necessitating more energy to run the car. However, EVs can be charged with electricity that is generated from solar panels and wind turbines.
What about putting stationary solar panels on your house or business? That is a great idea. Fixed panels can be set up so that they’re not obstucted, and angled optimally to the sun. And fixed wind turbines can work wonderfully as well.